H-ISDN meta-analysisHeart FailureOpen Access
Hydralazine-Isosorbide Dinitrate in Heart Failure with Reduced Ejection Fraction
Hydralazine-isosorbide dinitrate in heart failure with reduced ejection fraction: a meta-analysis
Why the trial?
Randomised trials of hydralazine-isosorbide dinitrate in heart failure span five decades and differ in populations and background therapy. Pooling them clarifies whether the combination reduces mortality across historical and contemporary settings.
Does hydralazine-isosorbide dinitrate reduce mortality in patients with heart failure with reduced ejection fraction?
Population
2,101 patients with HFrEF pooled from 3 randomised trials (incl. A-HeFT, H-HeFT)
Comparison
Hydralazine-isosorbide dinitrate vs control arms of the pooled trials
Design
Meta-analysis of 3 randomised trials
Key result
Hydralazine-isosorbide dinitrate was associated with a reduction in all-cause death (HR 0.71; 95% CI 0.58-0.87) and cardiovascular death (HR 0.65; 95% CI 0.47-0.90).
Authors
Discussion
Key questions
Member takes
Where experts stand
Experts see the H-ISDN meta-analysis mortality signal as noteworthy but are cautious, given a neutral individual trial (H-HeFT) and acknowledged heterogeneity that makes firm practice conclusions difficult.
The meta-analysis pooling three trials showed meaningful reductions in all-cause and cardiovascular death with hydralazine-isosorbide dinitrate, but the largest new trial (H-HeFT) missed its primary endpoint on its own. Expert commentary has focused on summarizing the findings rather than taking strong stances, and no one has called this practice-changing. The open question is whether these pooled mortality results are robust enough to shift guideline recommendations beyond the current race-based indication.
1 take classified by contention axis so far — the map appears as more land.
Still unclear
It remains unclear whether guideline committees will broaden the H-ISDN indication to a wider HFrEF population based on the pooled mortality data, especially given that H-HeFT alone was neutral and hospitalization results were inconsistent. No expert has weighed in on whether the heterogeneity in trial design and background therapy undermines the meta-analytic signal enough to warrant further study.
Key expert perspectives
C. Michael GibsonInterventional / Structural Cardiology · Beth Israel Deaconess Medical CenterResults readoutAug 30Meta-analysis shows 29% reduction in all-cause mortality and 35% in CV mortality with H-ISDN
Gibson discussed both the neutral H-HeFT trial (stopped early, no reduction in the primary composite) and the meta-analysis showing significant reductions in all-cause death, CV death, and first HF hospitalization across three pooled RCTs. His posts served as interview-based summaries with linked video and slides.
MGMartha GulatiCardiologistResults readoutAug 30
H-HeFT missed its primary endpoint in a broader HFrEF population
Gulati reported the H-HeFT results, noting 592 patients were randomized to H-ISDN versus placebo and the primary endpoint was not met (HR 0.90, 95% CI 0.67-1.21). Her post highlighted the neutral finding without editorializing on its implications.
Distilled from their postX post
Overview
May support use in ACEI-intolerant HFrEF; leaves open net benefit in contemporary regimens due to heterogeneity.
Key Points
- To evaluate the impact of hydralazine-isosorbide dinitrate on mortality and hospitalizations in patients with heart failure with reduced ejection fraction.
- Meta-analysis pooling 3 randomized controlled trials (including A-HeFT and H-HeFT) comprising 2,101 patients.
- Evaluated outcomes of all-cause death, cardiovascular death, and heart-failure hospitalization across trials with varying follow-up durations and background therapies.
- Hydralazine-isosorbide dinitrate was associated with a significant reduction in all-cause death (HR 0.71, 95% CI 0.58 to 0.87) and cardiovascular death (HR 0.65, 95% CI 0.47 to 0.90).
- Heart-failure hospitalization outcomes were inconsistent across trials, with marked heterogeneity in trial design, follow-up, background therapy, and tolerability issues.
Evidence details
Limitations & tradeoffs
Design limitations
substantial heterogeneity in trial design, follow-up duration and background therapy across the pooled trials.
Statistical certainty
heart-failure hospitalisation results were inconsistent across trials with no pooled estimate reported, and the investigators themselves concluded that firm conclusions about cardiovascular outcomes are difficult.
Patient burden
tolerability issues with H-ISDN complicate interpretation of the mortality findings.
Structured PICO
Does hydralazine-isosorbide dinitrate reduce mortality in patients with heart failure with reduced ejection fraction?
P
Population
2,101 patients with heart failure pooled from three randomised trials.
I
Intervention
Hydralazine-isosorbide dinitrate (H-ISDN)
O
Outcome
All-cause deathhard clinical
Although hydralazine-isosorbide dinitrate is associated with reduced all-cause and cardiovascular mortality in HFrEF, significant trial heterogeneity and tolerability issues prevent firm clinical conclusions.
Main Result
Hazard Ratio: 0.71 (95% CI 0.58–0.87)
Limitations
- Substantial differences in trial design, duration of follow-up, and background therapy
- Heterogeneity across trials
- Tolerability issues
- Substantial differences in trial design
- Substantial differences in duration of follow-up
- Substantial differences in background therapy
- Heterogeneity
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Cite This Study
Morten Schou (2026) conducted a meta-analysis in Heart failure with reduced ejection fraction (n=2,101). Hydralazine-isosorbide dinitrate (H-ISDN) was evaluated on All-cause death (HR 0.71, 95% CI 0.58-0.87). Hydralazine-isosorbide dinitrate was associated with a reduction in all-cause death (HR 0.71; 95% CI 0.58-0.87) and cardiovascular death (HR 0.65; 95% CI 0.47-0.90).